Arcuate line

Description

The arcuate line is the level in the posterior lamina of the rectus sheath where the aponeuroses of the transversus abdominis and the internal oblique pass anterior instead of posterior to the rectus abdominis muscle. It forms a distinct transverse arching inferior border to the posterior lamina. Below this line the rectus abdominis is bounded by the transversalis fascia posteriorly It is approximately two to three centimeters below the level of the umbilicus.